"A couple of years"...
How long have you had that CRT for?
Will Mrs PL allow you to upgrade the still perfectly functional 2014 TV to a 4k TV in 2 years time?
If I were buying now, I'd be buying 4k or waiting a bit until 4k came within budget.
Assume you mean 48-50 inches (not cm) - it looks like about £1k is what you'd need to be spending -...